With 38mm Space Grey Apple Watch Series 3 Cellular stay connected even without your phone. The watch comes with a Space Grey aluminum chassis and a Black Sport band. It is designed for users looking for the next generation of connectivity. The Cellular Apple Watch has an electronic SIM built-in so you can make and receive calls, send texts, and see app notifications.  This Apple Watch features an 1.5" OLED Retina display with 340 x 272 display resolution and digital crown.

The Apple Watch features an optical heart sensor to quickly check your heart rate, and an electric heart sensor that works with the crown to generate an ECG (electrocardiogram). Workouts are easier than ever to track thanks to the built-in GPS and altimeter, so you get a clear summary of your speed, distance, climb, and route. The Apple watch connects to your iPhone via Bluetooth 4.2. It can also connect directly to the Internet via Wi-Fi. The internal battery lasts for up to 18 hours of normal use.

HEART RATE MONITOR

Check your heart rate at any time with the Apple Watch's built-in heart rate monitor. The irregular heart rhythms (arrhythmias), high heart rates, and low heart rates, can all be indicators of a possible underlying problem. The Apple Watch is engineered to monitor this reading and alert you to any irregularities.

GPS

The built-in GPS lets you navigate and get accurate workout data. It connects quickly to GPS satellites and records distance, speed, and pace for your workout as well as the route you traveled and whether you're walking, running or cycling.